7 citations · 13 across the 14 of their papers we have counts for
15 papers
Multifactorisations and Divisor Functions
Ambrose D. Law, Matthew C. Lettington, Karl Michael Schmidt
We consider a joint ordered multifactorisation for a given positive integer into parts, where , and each part is split into one…
Continuum limits for discrete Dirac operators on 2D square lattices
Karl Michael Schmidt, Tomio Umeda
We discuss the continuum limit of discrete Dirac operators on the square lattice in as the mesh size tends to zero. To this end, we propose the most natural and simpl…
Integer matrix factorisations, superalgebras and the quadratic form obstruction
Nicholas J. Higham, Matthew C. Lettington, Karl Michael Schmidt
We identify and analyse obstructions to factorisation of integer matrices into products or of matrices with rational or integer entries. The obstructions arise as qua…
The inverse problem for a spectral asymmetry function of the Schrödinger operator on a finite interval
B. Malcolm Brown, Karl Michael Schmidt, Stephen P. Shipman +1
For the Schrödinger equation on a finite -interval, there is defined an "asymmetry function" , which is entire of order and type in…
Divisor Functions and the Number of Sum Systems
Matthew C. Lettington, Karl Michael Schmidt
Divisor functions have attracted the attention of number theorists from Dirichlet to the present day. Here we consider associated divisor functions which for non-neg…
On the Structure of Additive Systems of Integers
M. N. Huxley, M. C. Lettington, K. M. Schmidt
A sum-and-distance system is a collection of finite sets of integers such that the sums and differences formed by taking one element from each set generate a prescribed arithmetic…